1. Field of the Invention
The present invention relates to a method and an apparatus for processing on-line data in a decentralized processing system consisting of a multiplicity of processors linked through a transmission medium.
2. Description of the Prior Art
A system for processing on-line data in a decentralized processing system as described in Japanese Patent Laid-Open No. 146361/1982. That system includes a transmission control processor which is connected to a processor and sends the data that is required by the processor to the data area on a transmission medium with the content code thereof as a key. The program in the processor stores the data that is sent in the data area. However, the size and head address of the data area must be determined at the time of preparing the program.
If data of an increased size is directly stored by the program, therefore, other areas positioned just behind the above data are destroyed unless the following procedures are taken:
(1) Correction of the data areas only is not sufficient when the data is directly referred to by a head address of the program. Therefore, the processor for developing the program must link again the data area and the program that makes reference to the data, and must load them at one time onto a processor that needs them under an off-line condition. PA1 (2) To effect the above linkage, the processor for developing the program manages the memory information specific to the processor that receives the program, and further manages the program and the data. PA1 (3) The processor for developing the program designates a loading address so that the address at the time of linkage agrees with the address at the time of loading. PA1 (1) If data having an increased size is directly stored by the program, other areas arranged just behind the data are destroyed and are not referred to. PA1 (2) The data are not stored under an on-line condition, and the program must be corrected. PA1 (3) The processor for developing the program must manage the memory information specific to the processor, must manage the program and information related to the data that are necessary for developing and correcting the program, and must further manage the loading addresses for designating the processors.
According to the above prior art, however, there is no attempt to dynamically cope with the data of variable lengths on the transmission medium, and problems arise as described below.
Because of these reasons, the processors could not maintain autonomy to carry out the processing relying solely upon their own internal information without giving instructions to other processors or without being instructed by other processors, making it difficult to maintain flexibility in the maintenance and extension.